Field of the Invention
Embodiments presented in this disclosure generally relate to wind tower damping system, and more specifically, to decoupling a control signal from the activation strategy used to reduce oscillations in the wind turbine.
Description of the Related Art
Tower oscillations may arise each time a rotor blade passes the tower and generates wind that pushes against the tower. Another source for tower oscillations is wind turbulence which may cause periodic or instantaneous movements in the wind turbine tower. Oscillations and vibrations in a tower of a wind turbine may fatigue the wind turbine. If left unchecked, these oscillations can have a detrimental effect on the lifespan of the wind turbine.
One way of compensating for tower oscillations is to design the tower with these oscillations in mind. For example, tower oscillations may be reduced by making the tower stiffer, designing the blades to mitigate oscillations, reducing the weight of the nacelle and rotor, etc. But these design measures often conflict with other desired qualities of the wind turbine such as low cost and high efficiency. As such, some turbines include a tower damping system that is used to actively counter tower oscillations and vibrations detected in the turbine.